Parametric Study of Specific Buckling Load of Cylindrical Grid Stiffened Composite Shells

Abstract

In this paper, specific buckling load of a cylindrical grid stiffened shell, which has been created by a Kagome unit cells, has been investigated. First, a single unit cell has been analyzed individually and the forces and moments caused by each unit cell have been transferred to the skin of cylinder. Thus, the equivalent cylindrical shell, which consists of the shell and the unit cells stiffeners, is obtained. Then the equivalent cylindrical shell is analyzed as a composite cylindrical shell. After introducing the approximate displacement functions and Ritz method buckling load will be achieved. The specific buckling load of the cylinder will be presented by changing some parameters simultaneously. The winding angle of the shell, the cross section size of ribs, shell thickness, the number of the iso-angle ribs and ribs axial pitch are these parameters. All these results are presented for Glass/Epoxy material. Figures of specific buckling load versus new two parameters (rib pitch and rib numbers) have been shown and discussed. Also, comparison between presented theory and other papers results will be done to verify the analytical results. At last, a parametric study is discussed to check the geometrical parameters’ effects on the specific buckling load for different kinds of mentioned grids.